People may observe an event with one of their five senses (including: sight, hearing, smell, taste, and touch), but not be able to perceive the event with another of those senses. For example, a person may observe one or more events visually that occur so far from the location of the event(s), that the person cannot hear sounds that accompany the events. Examples of such visual events could be sea waves on the horizon, trees swaying in a strong wind in the distance, birds that fly high in the sky, and cars on a street viewed from within a skyscraper, etc. Also, when people look at pictures, they may want to hear sounds that are associated with the visual events depicted.